The main qualities which consumers require from rolled steel products are, inter alia, an elastic limit which is as high as possible for the grade of steel used and, according to the conditions and use for which the product is intended, fatigue strength, ductility, weldability, and perhaps drawability of a satisfactory quality.
Obtaining these qualities requires, among other things, the use of a method of hardening either by precipitation, for example by means of the addition of alloying elements, or by work-hardening, for example by drawing or cold-twisting. However, these two known methods have the disadvantage of being costly.
The object of the present invention is a method which enables the above drawback to be obviated, as a result of the adaptation of a heat treatment to the composition of the steel in order to create suitable metallic microstructures.